Rolling mill coil-forming laying head with path or pipe having nested layer construction

ABSTRACT

A rolling mill coil-forming apparatus includes a rotating quill that supports an elongated path hollow structure, such as a laying head pipe, for receiving elongated material after it has been rolled. A portion of the elongated structure or the entire structure is formed from nested, enveloping layers by inserting layers of pipe or other elongated hollow structure into each other. Elongated path hollow structures formed from nested layers can be constructed in any three dimensional compound curve shape that can replicate the smooth, continuous curve elongated material transport path of known laying pipes, or any other desired path.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to co-pendingU.S. Provisional application Ser. Nos. 61/539,014, 61/539,062, and61/539,069, filed 26 Sep. 2011; and U.S. Provisional Application Ser.Nos. 61/540,590; 61/540,602; 61/540,609; 61/540,617; and 61/540,798,filed 29 Sep. 2011, all of which are entirely incorporated herein byreference as if fully set forth below.

BACKGROUND

1. Field

Embodiments of the present invention relate to rolling mill coil-formingapparatuses, often referred to as laying heads, and more particularly toreplaceable laying head pathways, such as laying head pipes, in layingheads.

2. Description of the Prior Art

Rolling mill coil-forming laying head apparatuses form moving rolledelongated material into a series of helical continuous loop rings. Thoserings may be further processed downstream by bundling them into coils ofthe helical turns. Known laying heads are described generally in U.S.Pat. Nos. 5,312,065; 6,769,641; and 7,011,264, the entire contents ofall of which are hereby incorporated by reference as if fully containedherein.

As described in these patents, rolling mill laying head systems comprisea quill, pipe support and a laying head pipe. The quill and pipe supportare adapted to rotate the laying head pipe such that it can receiveelongated material into its entry end. The laying head pipe has a curvedintermediate portion that is surrounded by the quill's flared sectionand an end portion that projects radially outwardly from and generallytangential to the quill's rotational axis. In combination, the rotatingquill and the laying head conforms the rolled material into a helicalcurved shape. The laying head pipe may be replaced with one of adifferent profile and/or diameter in order to reconfigure the layinghead to accommodate different dimensioned rolled material or to replaceworn pipes.

Further helical profiling of the rolled material is accomplished in arotating helical guide that includes troughs for receiving the rolledmaterial about its outer circumference. The helical guide described inU.S. Pat. No. 6,769,641 is of segmented, sector-shaped, modular rimconstruction with the circumferential troughs formed within the rimsectors.

A generally annular ring or shroud, also commonly referred to as an endring or guide ring, has a guide surface that circumscribes the layinghead pipe discharge end and helical guide, so that the elongatedmaterial is confined radially as it is discharged in now fully coiledconfiguration to a conveyor for subsequent bundling and otherprocessing. A pivoting tripper mechanism, including one or more tripperpaddles, may be positioned at approximately the six o'clock or bottomposition of the end ring/shroud distal the quill. Varying the pivotattack angle of the tripper mechanism relative to the ring/shroud innerdiameter surface is useful to control elongated material coiling, forexample to compensate for varying elongated material plasticitythickness, composition, rolling speed and cross sectional structure.

Laying Head Pipe Design and Operational Constraints

As previously noted the hollow laying head pipe in combination with therotating quill and pipe support, conform the rolled material into ahelical curved shape. Typically, the laying head pipe is formed from acontinuous length of symmetrical steel pipe or steel tubing that is bentin a forming jig by application of external heat and mechanical force toconform to the desired generally helical profile. Steel pipe or tubingis generally chosen for construction of laying head pipes for relativeease of workability into the desired final generally helical shape andrelatively low material purchase cost. But commercial steel pipe ortubing have relatively low hardness: an undesirable limiting factor forrolling mill operation, productivity and maintenance.

Elongated material that is advancing at speeds up to approximately 500feet/second (150 m/sec) is received in the laying head system intake endand discharged in a series of continuous coil loops at the dischargeend. At such speeds, the hot rolled products exert a punishing effect onthe laying head pipes, causing internal pipe surfaces to undergo rapidlocalized frictional wear and premature failure. Also, as the layinghead pipes wear, their ability to deliver a stable ring pattern to thelooped coil receiving conveyor at the discharge end of the laying headdeteriorates. Unstable ring patterns disturb cooling uniformity and alsocontribute to coiling mishaps commonly referred to as “cobbling.”

For a number of years, it has been well accepted that laying head pipeswith reduced bore sizes provide a number of significant advantages. Byradially constricting the hot rolled products within a smaller space,guidance is improved and the ring pattern delivered to the coolingconveyor is more consistent, making it possible to roll at higherspeeds. Unfortunately, however, these advantages have been offset to alarge extent by significantly accelerated pipe wear due to the higherspeed of the product. Also, the reduced bore size pipe can only be usedwith small diameter products, so it must be replaced by a larger boresize pipe for coiling of larger diameter products.

Frequent and costly mill shutdowns and preventive maintenance arerequired to replace prematurely worn laying head pipes and to addressproblems associated with elongated material cobbling. If a laying headpipe becomes so worn that it suffers a pipe wall rupture, the cobblingmishap can impact elongated material feed upstream of the laying head.From a wear resistance point of view it is desirable to form the layinghead pipe inner wear surface from relatively hard low surface frictionsteel and further desirable to perform further surface hardening andheat treatment, but such wear treatment steps must be balanced with easeand cost of pipe fabrication.

Thus, in the past, those skilled in the art have deemed it necessary tocompromise laying head pipe design and performance by employing largerbore laying head pipes and rolling at reduced speeds below the rateddesign speeds of the mills. The combination of larger than desiredlaying head pipe internal diameter and reduced rolling speeds have beenimplemented in order to schedule preventive maintenance pipe replacementduring scheduled maintenance “downtime”. Conventional and current layinghead pipes must be replaced after processing quantities of elongatedmaterial of approximately 3,000 tons or less with standard carbon steelpipes, depending on diameter, speed and product composition.

Those skilled in the art have made repeated attempts at increasing theuseful life of laying head pipes for larger total processing tonnage, sothat more elongated material can be processed before replacement. Forexample, as disclosed in U.S. Pat. Nos. 4,074,553 and 5,839,684, it hasbeen proposed to line the laying head pipes with wear resistant insertrings that are inserted into an external laying head pipe casing.Adjoining rings within curved sections of the laying head pipe casinghave discontinuity gaps that are not desirable for smooth advancement ofelongated material that is being transported within the laying headpipe. U.S. Pat. No. 6,098,909 discloses a different approach where thelaying head pipe is eliminated in favor of a guide path defined by aspiral groove in the outer surface of a conical insert enclosed by aconical outer casing, with the insert being rotatable within the outercasing to gradually shift the wear pattern on the inner surface of theouter casing. It is not believed that the spiral groove conical insertapproach is readily compatible with all existing quill laying heads thatpresently incorporate laying head pipe structures.

Attempts have also been made at carburizing the interior laying headpipe surfaces in order to increase hardness and resistance to wear. Butthe carburizing process requires a drastic quenching from elevatedprocessing temperatures, which can distort the pipe curvature. Thecarburized layer has also been found to be relatively brittle and totemper down at elevated temperatures resulting from exposure to the hotrolled products.

The owner of this patent application has also disclosed the applicationof a boronized layer to the laying head pipe wear surfaces by subjectingthem to a thermochemical treatment in which boron atoms are diffusedinto the pipe interior to increase its hardness. See Patent CooperationTreaty Application entitled “Boronized Laying Pipe”, filed in the UnitedStates Receiving Office on Sep. 2, 2011, Serial No. PCT/US2011/050314.

The owner of this patent application has also disclosed a laying headpipe having inner and outer friction-tight engaged concentric layers inwhich the inner layer advances axially relative to the outer layerduring laying head operation due to centrifugal forces, differences inlocalized thermal expansion, and thermal cycling between the layers.Thus worn sections of the laying head pipe interior advance along thepipe interior so that a “fresh” unworn surface continually replenishesthe worn section. See Patent Cooperation Treaty Application entitled“Regenerative Laying Pipe”, filed in the United States Receiving Officeon Sep. 2, 2011, Serial No, PCT/US2011/050283.

SUMMARY

Accordingly, embodiments of the present invention include a rolling milllaying head elongated structure for retention and transport of elongatedmaterials in a laying head, so that the elongated material can beselectively coiled. The laying head path structure may perform thefunctionality of a conventional laying head pipe. In aspects of thepresent invention, portions of the laying head path structure or thestructure in its entirety is formed from nested, enveloping layers byinserting layers of pipe or other elongated hollow structure into eachother. In an exemplary embodiment the laying head path structure has anelongated hollow pathway structure having at least two layers; includingan inner layer defining an inner surface for transport of elongatedmaterials therein and a retention layer for retaining the inner layer.Laying head path structures that are formed from nested layers can becan be constructed in any three dimensional compound curve shape thatcan replicate the smooth, continuous curve elongated material transportpath of known laying pipes, or any other desired path. For example, alaying head elongated structure for transporting elongated materials canbe constructed of two or more layers of pipe or tubing of the same ordissimilar materials. A pipe layer may be constructed of a homogeneousmaterial or different materials may be joined to form the layer. Thefabricated layered structures facilitate formation of zones within thecomponent segment, such as including by way of example wear-resistantzones or friction reducing zones in the segment that are in directcontact with the elongated material. The innermost layer can be aregenerative layer that advances downstream the same direction as theelongated material, so that the upstream portion within a laying headpath internal wear zone constitutes afresh, unworn surface.

Another exemplary embodiment relates to a coil-forming apparatus layinghead system for coiling hot rolled elongated material, comprising aquill rotating about an axis, for discharging elongated material. Asupport is coaxial with the quill rotational axis. An elongatedtransport path hollow pathway structure, such as a laying head pipe, iscoupled to the support, for passage of elongated material there through.The elongated hollow pathway structure comprises an inner layer definingan inner surface for transport of elongated materials therein and aretention layer for retaining the inner layer. A portion of the hollowmember structure or the structure in its entirety may be formed fromnested, enveloping layers by inserting layers of pipe or other elongatedhollow structure into each other.

An additional exemplary embodiment of the present invention includes amethod for forming an apparatus for retention and transport of elongatedmaterials in a rolling mill coil-forming apparatus. The exemplaryembodiment method comprises providing an inner layer defining an innersurface for transport of elongated materials therein; providing aretention layer for retaining the inner layer; and inserting the innerlayer into the retention layer. The nested composite structure may beformed into a desired three dimensional curved shape of a laying headpath.

The features of aspects of the present invention may be applied jointlyor severally in any combination or sub-combination by those skilled inthe art. Further features of aspects and embodiments of the presentinvention, and the advantages offered thereby, are explained in greaterdetail hereinafter with reference to specific embodiments illustrated inthe accompanying drawings, wherein like elements are indicated by likereference designators.

DESCRIPTION OF THE DRAWINGS

The teachings of the present invention can be readily understood byconsidering the following detailed description in conjunction with theaccompanying drawings, in which:

FIG. 1 shows a side elevational view of a coil-forming apparatus layinghead system, in accordance with an exemplary embodiment of the presentinvention;

FIG. 2 shows a top plan view of the laying head system of FIG. 1, inaccordance with an exemplary embodiment of the present invention;

FIG. 3 shows a sectional elevational view of the laying head system ofFIG. 1, including its end ring and tripper mechanism, in accordance withan exemplary embodiment of the present invention;

FIG. 4 shows an elevational view of the discharge end of the laying headsystem of FIG. 1, including its end ring and tripper mechanism, inaccordance with an exemplary embodiment of the present invention;

FIG. 5 shows a known construction laying head transport path/pipe andtypical exemplary wear zones experienced during laying head operation;

FIG. 6 shows a perspective view of a laying head elongated materialtransport path pipe, in accordance with an exemplary embodiment of thepresent invention;

FIG. 7 shows a partially cut away axial cross-sectional view of thelaying head path pipe of FIG. 6;

FIG. 8 shows a radial cross-sectional view of the laying head path pipeof FIGs. 6 and 7, taken along 8-8 thereof;

FIG. 9 shows a partial cut away axial cross-sectional view of a layinghead path pipe, in accordance with another exemplary embodiment of thepresent invention;

FIG. 10 shows a radial cross-sectional view of the laying head path pipeof FIG. 9, taken along 10-10 thereof;

FIG. 11 shows a side elevational view of a laying head path pipe, inaccordance with an another exemplary embodiment of the presentinvention;

FIG. 12 shows a partial cut away axial cross-sectional view of thelaying head path pipe of FIG. 11;

FIG. 13 shows a radial cross sectional view of the laying head path pipeof FIG. 11, taken along line 13-13 thereof;

FIG. 14 shows a partial axial cross-sectional view of the laying headpath pipe of FIG. 11; and

FIGS. 15A-15C are diagrammatic depictions illustrating the forces actingon a laying head path pipe in accordance with embodiments of the presentinvention during heating and cooling cycles.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures.

DETAILED DESCRIPTION

After considering the following description, those skilled in the artwill realize that the teachings of the present invention can be utilizedin rolling coil-forming apparatus laying heads and more particularly tolaying head elongated transport path pipes or other equivalent elongatedstructures for laying heads. Aspects of the present invention facilitatelonger laying head path service life so that more tons of elongatedmaterial can be processed by the laying head before preventativemaintenance replacement. For example, it is possible to increase thelaying head elongated material processing speed so that more tons ofelongated material can be processed in a production shift without unduerisk of laying head path/pipe failure.

Laying Head System Overview

Referring generally to FIGS. 1-4, the coil-forming apparatus laying headsystem 30 coils rolled elongated material M, such as for example hotrolled steel. Elongated material M that is advancing at speed S, whichmay be as high as or greater than approximately 500 feet/second (150m/sec), is received in the laying head system 30 intake end 32 anddischarged in a series of continuous coil loops at the discharge end 34,whereupon the coils are deposited on a conveyor 40.

The laying head system 30 comprises a rotatable quill 50, a path 60 anda pipe path support 70. The path 60 defines a hollow elongated cavity toenable transport of the material M. Aspects of the present inventionallow the path to comprise a laying head pipe; indeed, the path 60 mayoccasionally be referred to as a laying head pipe herein.

The quill 50 can have a generally horn shape that is adapted to rotateabout an axis. The path 60 has a generally helical axial profile ofincreasing radius, with a first end 62 that that is aligned with therotational axis of quill 50 and receives elongated material M. The path60 has a second end that is spaced radially outwardly from and generallytangential to the quill 50 rotational axis and thus discharges theelongated material generally tangentially to the periphery of therotating quill. The path 60 is coupled to a pipe support 70 that is inturn coupled coaxially to the quill 50, so that all three componentsrotate synchronously about the quill rotational axis. Quill 50rotational speed is selected based upon, among other factors, theelongated material M structural dimensions and material properties,advancement speed S, desired coil diameter and number of tons ofelongated material that can be processed by the laying head pipe withoutundue risk of excessive wear. FIG. 5 shows conventional laying headpath/pipe 60 wear zones 66, 68 in which the pipe interior is subjectedto relatively higher wear rates than other portions of the pipe. Aspectsof the present invention address the higher wear rates by locallyhardening the zones 66, 68 and other portions or all other desiredzones. If desired the entire or equivalent elongated structure can behardened by application of aspects of the present invention.

In this embodiment, as elongated material M is discharged from thesecond end 64, it is directed into a ring guide 80 having guide rimsegments 82 into which are formed a guide trough channel 84 having ahelical pitch profile, such as that described in commonly owned U.S.Pat. No. 6,769,641. As the elongated material M is advanced through thering guide 80 it is continued to be conformed into a continuous loophelix.

As stated in the '641 patent, the segmented ring guide enablesrelatively easy reconfiguration of the ring guide helical diameter toaccommodate different elongated materials by changing the rim segments82 without disassembling and replacing the entire ring guide 80.

As previously noted, the elongated material M is configured into acontinuous looped coil as it rides within the ring guide 80 helicaltrough channel 84. Ring guide 80 is coupled to the pipe support 70 androtates coaxially with the quill 50. The helical trough 84 advancementrotational speed is harmonized with the elongated material M advancementspeed S, so there is little relative linear motion speed between the twoabutting objects and less rubbing wear of the trough 84 surfaces thatcontact the coiling material.

Stationary end ring 90 has an inner diameter that is coaxial with thequill 50 rotational axis and circumscribes the laying path/pipe 60second end 62 as well as the ring guide 80. The end ring 90 counteractscentrifugal force imparted on the elongated material M as it isdischarged from the laying head pipe 60 second end 62 and advances alongthe ring guide 80 helical trough channel 84 by radially restraining thematerial within the end ring inner diameter guide surface. High relativespeed between the advancing elongated material M and the stationary endring 90 causes rubbing wear on the end ring inner diameter guidesurface.

Referring to FIG. 1, elongated material M that is discharged from thecoil-forming apparatus laying head system 30 falls by gravity incontinuous loops on roller conveyor 40, aided by the downwardly angledquill rotational axis at the system discharge end 34. Tripper mechanism150 pivots about an axis abutting the distal_axial side of the end ring90 guide surface. That pivotal axis is generally tangential to the endring 90 inner diameter guide surface about a pivotal range of motion θ.As is known, coiled material M coiling characteristics and placement onthe conveyor 40 can be controlled by varying the pivotal angle θ.

Path Fabrication

Embodiments of the present invention include a rolling mill laying headpath structure, for retention and transport of elongated materials in alaying head, so that the elongated material can be selectively coiled. Aportion of the path structure or the structure in its entirety is formedfrom nested, enveloping layers by inserting or nesting layers ofstraight pipe or other elongated hollow structure into each other andthen bending the nested structure into the final desired threedimensional shapes, as is done with known laying head pipes.Alternatively or additionally some of the nested structures can bepreformed into a three dimensional profile and then joined with othernested layers. The fabricated structures facilitate formation of zoneswithin the component, such as including by way of example wear-resistantzones or friction reducing zones. The zones can be formed during thepath/pipe structure fabrication process, such as by inserting pipesconstructed of different material into each other or by abuttingsections of different materials next to each other in a given layer.

FIGS. 6-8 show a laying head path 260 that has a generally cylindricalouter profile conforming to known laying head pipes, for directsubstitution in a known laying head such as the one shown in FIGS. 1-5.Laying head path 260 has a first intake end 262 with an annularretaining collar 262A and a second discharge end 264. The laying headpath 260 is a composite structure fabricated from nested subcomponentsincluding an outer steel pipe or tube 261 and an inner pipe or tube 263formed from a harder non-ferrous material, such as stainless steel ortungsten carbide. The inner layer 263 has a continuous inner surface263A for contact with elongated material that is transported through thelaying head pipe. If the inner layer 263 or that of other embodiments isconstructed of spliced segments in abutting axial relationship with anadjoining segment the inner surface 263A is effectively continuous(i.e., gaps between adjoining sections are sufficiently smaller than theelongated material diameter and circumference so that any such gaps donot impede transport of the elongated material through the laying headpath structure 260). The inner surface 263A may be surface coated ortreated to harden the surface or provide a friction reducing zone thatmay include a solid lubricant such as graphite.

FIGS. 9 and 10 show another embodiment of the laying head path 360 ofthe present invention that has a first intake end 362 with an annularretaining collar 362A. The laying head path 360 is a composite structurefabricated from nested subcomponents including an outer steel pipe ortube 361 and an inner pipe or tube 363 formed from tungsten carbidetubing or tungsten carbide sintered to form a generally tubular hollowstructure. The inner tube 363 has a continuous inner surface 363A forcontact with elongated material that is transported through the layinghead path. The inner surface 363A may be surface coated or treated toharden the surface or provide a friction reducing surface. An optionalinsulating high temperature grout layer 380 may be interposed betweenthe outer pipe 361 and the inner pipe 363.

As shown and described in commonly owned Patent Cooperation TreatyApplication entitled “Regenerative Laying Pipe”, filed in the UnitedStates Receiving Office on Sep. 2, 2011, Serial No. PCT/US2011/050,283,a laying head pipe having inner and outer friction-tight engagedconcentric layers in which the inner layer advances axially relative tothe outer layer during laying head operation due to centrifugal forces,differences in localized thermal expansion, and thermal cycling betweenthe layers. Thus worn sections of the laying head pipe or otherelongated laying head path interior advance along the pipe interior sothat a “fresh” unworn surike continually replenishes the worn section.Specifically, referring to FIGS. 11-15C, the laying head pipe 460 inaccordance with the present invention, has an outer tube or pipe 461,constructed from ferrous metal, such as steel, with that pipe having anentry section 462 aligned with axis A, an intermediate section 28 bcurving away from axis A, and a delivery section 28 c having a radiusmeasured from axis A.

An inner tube or pipe 463 has entry, intermediate and delivery sectionsrespectively lining the entry, intermediate and delivery sections of theouter tube 461, and is constructed of non-ferrous material such asstainless steel or tungsten carbide. The inner tube 463 is constrainedagainst movement relative to the outer tube 461 solely by frictionalcontact with the outer tube. It has been observed that in service, theinternal surface of a laying head pipe 463A is prone to acceleratedlocalized wear in zone Z, approximately at the junction of entry section28 a and intermediate section 28 b, and again in zone Z₂ approximatelyat the junction between intermediate section 28 b and the deliverysection 28 c. If left unchecked, this localized wear results inpremature grooving of the interior pipe surface, followed by abreakthrough of the product through the wall of the laying head pipe.

In accordance with the present invention, this wear problem is addressedby lining the outer tube 461 with the inner tube 463, and by allowingthe inner tube to be restrained against movement within the outer tubesolely by frictional contact between their respective outer and innersurfaces.

When the laying head path laying head pipe 460 is in service, the innertube 463 is heated by contact with the hot rolled product M. Typically,the hot rolled product will be at a temperature of about 900-1100° C.,which will result in a heating of the inner tube 463 to an elevatedtemperature of about 400° C. The outer tube will typically have a lowertemperature due to its exposure to the surrounding atmosphere.

Additionally, as shown in FIG. 12, the intermediate section 28 b of thelaying head pipe will be subjected to a centrifugal force F_(CEN) as aresult of its rotation about axis A. This force can be resolved into aforce F_(N) normal to the guide path of the laying head pipe, and driveforce F_(D) exerted towards the delivery end of the laying head pipe.Driving force F_(D) will be supplemented by an additional driving forceexerted by the hot rolled product passing through the laying head pipe.

As shown in FIG. 15A, as the inner tube 463 is being heated by contactwith the hot rolled product, it will undergo expansion, exerting forcesin opposite directions towards the entry end (arrow F_(EE)) and thedelivery end (arrow F_(DE)). The expansion forces F_(EE) and F_(DE) aresufficient to overcome the frictional resistance F_(E). The expansionforce F_(EE) is overcome by the sum of expansion force F_(DE) and thedriving force F_(D), resulting in the inner tube 463 being shiftedincrementally within the outer tube 461 towards the delivery end of theouter tube.

As shown in FIG. 15B, when the temperature of the inner tube 463stabilizes, there are no expansion or contraction forces. The frictionalforce F overcomes the driving force F_(D), and the inner tube remainsfixed within the outer tube.

As shown in FIG. 15C, when the inner tube 463 is cooled, it will undergocontraction, again exerting opposite forces towards the entry end (arrowC_(EE)) and the delivery end (arrow C_(DE)). The forces C_(EE) andC_(DE) are sufficient to overcome the frictional force F_(F). Thecontraction force C_(EE) is overcome by the sum of contraction forceC_(DE) and the driving force F_(D), resulting in the entry end of theinner tube 463 being shifted incrementally within the outer tube 461towards the delivery end 464 of the outer tube.

Thus, it will be seen that as the laying head path laying head pipe 460undergoes heating and cooling cycles, the inner tube 463 will be shiftedincrementally in one direction towards the delivery end 464 of the outertube 461. This incremental shifting will change and thus renew theinternal surfaces of the inner tube that are in frictional contact withthe hot rolled product, and in so doing, will avoid prolonged frictionalcontact at any one given area. The axially overlapping nestedconfiguration of the inner tube 463 and inner sleeve 470 compensates foraxial advancement of the inner tube toward the delivery end 464, so thattwo nested pipe layers circumscribe the elongated material M.

For all laying head elongated path structures embodiments of the presentinvention herein, the laying path elongated structure inner diameter canbe varied, such as by varying the wall thickness of the inner pipe,while if desired, maintaining the same outer pipe diameter. The pairs ofinner and outer tubes or other elongated structure members of theembodiments herein, such as 261/263, 361/363 and 461/463, may befabricated from various ferrous or non-ferrous materials, includingceramics, preferred examples comprising ferrous metals, nickel basedalloys, cobalt based alloys and titanium based alloys, as well asdeposited nano particle coatings of any of them. More specifically theouter hollow elongated structure of the laying head path comprises anydesired material or metal (steel often being a cost effective choice) ornon-metallic structures, such as filament reinforced carbon fiber. Theinner surface of a filament reinforced carbon fiber or other outerelongated path member/pipe may include an inner layer formed from a nanoparticle layer of non-ferrous material, such as stainless steel ortungsten carbide, deposited thereon. The deposited nano layer functionsas the equivalent of a separate inner pipe pathway structure. The innerpipe or other functionally equivalent inner layer path forming structureis comprises ferrous or non-ferrous materials, including ceramic, nanoparticle material coatings, steel, or non-ferrous alloys such asstainless steel, tungsten carbide or so-called super alloys, such as forexample Inconel®, Waspaloy® or Hastelloy®. Other non-ferrous metals maybe substituted for the inner or outer pipe layers, comprising by way ofexample stainless steel, tungsten carbide, and so-called super alloys,such as for example Inconel®, Waspaloy® or Hastelloy®, ceramics or nanoparticle layers of the above. The inner surface of the inner tube thatis in contact with the elongated material may be treated or coated(including nano particle coatings) to increase surface hardness, reducefriction or decrease thermal ablation.

Although various embodiments, which incorporate the teachings of thepresent invention, have been shown and described in detail herein, thoseskilled in the art can readily devise many other varied embodiments thatstill incorporate these teachings.

What is claimed is:
 1. An apparatus for retention and transport ofelongated materials in a rolling mill coil-forming apparatus,comprising: an elongated hollow pathway structure having at least twolayers including: an inner layer defining an inner surface for transportof elongated materials therein; and a retention layer for retaining theinner layer.
 2. The apparatus of claim 1, the layers selected from thegroup consisting of similar and dissimilar materials.
 3. The apparatusof claim 1, the inner layer comprising laterally adjoining segments offerrous and non-ferrous material.
 4. The apparatus of claim 3,comprising non-ferrous material in segments having higher wear rates. 5.The apparatus of claim 1, comprising a grout layer interposed betweenthe inner layer and the retention layer.
 6. The apparatus of claim 1,the inner layer and the retention layer are in circumferential frictioncontact with each other, with the inner layer advancing axially withrespect to retention layer during repetitive heating and cooling cyclesof the elongated pathway structure.
 7. The apparatus of claim 1, theinner layer having a hardened inner surface.
 8. The apparatus of claim1, the inner surface having a zone selected from the group consisting ofwear resistant zone, projecting material standoff, material transportguide structures and friction reducing zone.
 9. The apparatus of claim1, the inner layer comprising non-ferrous materials selected from groupconsisting of nickel based alloys, cobalt based alloys and titaniumbased alloys, stainless steel, tungsten carbide, ceramics, superalloysand nano layers of said non-ferrous materials deposited on the innersurface.
 10. A rolling mill coil-forming apparatus comprising: a drivenrotating quill; and an elongated hollow pathway structure having atleast two layers including: an inner layer defining an inner surface fortransport of elongated materials therein; and a retention layer forretaining the inner layer.
 11. The apparatus of claim 10, the layersselected from the group consisting of similar and dissimilar materials.12. The apparatus of claim 10, the inner layer comprising laterallyadjoining segments of ferrous and non-ferrous material.
 13. Theapparatus of claim 10, the inner layer and the retention layer are incircumferential friction contact with each other, with the inner layeradvancing axially with respect to retention layer during repetitiveheating and cooling cycles of the elongated pathway structure.
 14. Theapparatus of claim 10, the inner surface having a zone selected from thegroup consisting of wear resistant zone, projecting material standoff,material transport guide structures and friction reducing zone.
 15. Theapparatus of claim 10, the inner layer comprising non-ferrous materialsselected from group consisting of nickel based alloys, cobalt basedalloys and titanium based alloys, stainless steel, tungsten carbide,ceramics, superalloys and nano layers of said non-ferrous materialsdeposited on the inner surface.
 16. The apparatus of claim 1, formed byinserting the inner layer into the retention layer.
 17. The apparatus ofclaim 16 formed by bending the combined inner and retention layers. 18.A method for forming an apparatus for retention and transport ofelongated materials in a rolling mill coil-forming apparatus,comprising: providing an inner layer defining an inner surface fortransport of elongated materials therein; providing a retention layerfor retaining the inner layer; and inserting the inner layer into theretention layer.
 19. The method of claim 18, further comprising bendingthe combined inner and retention layers.
 20. The method of claim 19comprising affixing ends of at least the retention layer to an adjoiningportion of said apparatus for retention and transport of elongatedmaterials.